ACF said its workers had been lined up, forced to kneel and each shot in the head.

The killings happened as security forces took control of Muttur, while fighting Tamil Tiger rebels.

Other allegations of war crimes overshadowed a Commonwealth summit held in Sri Lanka this month. Names and photos

Human rights activists have previously accused Sri Lanka's security forces of the killings but ACF said it had held off, awaiting the official version of events.

It then decided to publicly denounce the perpetrators because "relevant domestic mechanisms have been exhausted, witnesses have been silenced and the internal Sri Lankan investigation has become a farce".

According to ACF's report, all of the alleged victims were Tamils. They are listed by name, along with their photographs.